Thermoelectric materials and devices may be utilized to obtain electrical energy from a thermal gradient. Current thermoelectric materials have a limited thermoelectric conversion efficiency which may be defined in terms of the formula ZT=TS2γ/κ. The ZT of the above formula or figure of merit is related on the macroscopic transport parameters of the material including the Seebeck coefficient S, the electrical conductivity γ and the thermal conductivity κ.
In order to improve the thermoelectric conversion efficiency one may increase the Seebeck coefficient and electrical conductivity while lowering the thermal conductivity. Increasing the ZT is difficult as the three parameters S, γ and κ are interrelated. For example, doping of a specific material may increase the electrical conductivity while decreasing the Seebeck coefficient and increasing the thermal conductivity. There is therefore a need in the art for a material having a ZT improved over current prior art materials. There is also a need in the art for increasing the thermoelectric conversion by increasing or maintaining the Seebeck coefficient and electrical conductivity while lowering a thermal conductivity.
Nanostructured materials may be utilized to produce thermoelectric nanoparticles and materials that may be utilized to form a thermoelectric composite material. However, such nanostructured materials may be difficult and expensive to manufacture and may be difficult to process to form a composite material. There is therefore a need in the art for a thermoelectric nanostructured material and a process for producing the same that produces materials having an increased thermoelectric conversion efficiency. Additionally, there is a need in the art for a process for producing the thermoelectric nanoparticles that is cost efficient and scalable. Further, there is a need in the art for a process for producing thermoelectric composites having improved properties and maintains a desired particle size that overcomes technical problems of manufacturing in the prior art.